With the popularity of a touch tablet computer, a user requirement on a display is getting higher and higher. A part of current tablet computers can realize naked-eye stereoscopic display. For example, a viewpoint image displayed by each sub-pixel column 101 enters a human's eye through a grating 102. But, as illustrated in FIG. 1, a first viewpoint image displayed by a first sub-pixel column can be seen in a first viewing angle region, which is a gray shaded region defined by a line A11 and a line A12, a second viewpoint image displayed by a second sub-pixel column can be seen in a second viewing angle region, which is a display region marked with dots and defined by a line A21 and a line A22, and a third viewpoint image displayed by a third sub-pixel column can be seen in a third viewing angle region, which is a region marked with vertical lines and defined by a line A31 and a line A31. In FIG. 1, 1 stands for a first sub-pixel unit, 2 stands for a second sub-pixel unit, 3 stands for a third sub-pixel unit; however, because the first viewing angle region, the second viewing angle region and the third viewing angle region are very close to each other, and the viewing angle range is limited within the range of 180 degrees, the interference occurs between the viewpoint images, and it can not be achieved that multiple persons view one display.